Hybrid build questions

[John]

Hey guys,

I'm getting tired of the power the EJ20R is giving me...I'm as well starting to have various issues with my current longblock, so its time to upgrade.

My car is a 95 Legacy. I have a full stand alone (Megasquirt), Walboro 255, fmic, rotated, etc.

First, I'll start off by saying my goals. I would like to put down between 500 - 550 on the local dynojet. I would like to do this on 93 octane pump gas. I know its difficult to do, but its been done before.

I'll be using the EJ257 block with a built bottom end. As for the heads, I think I'm going to keep the EJ20R heads, but send them out to be rebuilt and port/polished.

I guess my biggest issue is what turbo to use. My TD04 will never provide much more power then it already is (its tuned at 15psi)....What route should I go for with the turbo?

Injectors are another area I'm uncertain of. I'm using 660 side feeds right now. Will I have to bump up to something like 1000 top feed? As well, is my 255 fuel pump enough to support 500hp, or will I have to run dual pumps?

I'll be doing the build myself, however I will send it to Topspeed (http://www.topspeedtuned.com/) to have it tuned. A lot of the local Subaru guys have used Topspeed with excellent results.

Any advise you guys can give me would be great. I posted something on NASIOC some time ago, but didn't really get any straight answers.

 

[HolyCrapItsFast]

Are the heads from a 95 legacy? Are they dual cam?

I think 500 is possible but as you suggest it is going to take allot on pump. You need to carefully think about ALL the supporting mods and how each one complements the other. Exhaust, Headers, Maf Housing, Turbo Inlet, Intercooler, Ect should all be taken into consideration. For sure you will need a much larger turbo. I'm guessing something with a 55lbs/min compressor or larger and supporting cams. I'm thinking 272's. I also believe you will need a deatschwerks 300lph pump at the minimum. I don't think you need dual pumps. For injectors, Five0 makes 1000cc sidefeeds so you can drop those in and be done and they are dirt cheap also.

Also you should really think about internals on the 2.5 block because it won't last very long on 500hp if you plan on using the stock rods and pistons.

I would have a chat with top speed to see what they think you will need to achieve your goal.

 

[John]

My EJ20R heads have 252 cams in them. I plan on building the shortblock to support the power as well. As far as MAF, I don't run a MAF. Its MAP based

Here is more details on my current setup

The EJ20R is a JDM 96 - 98 Legacy GT-B engine. It was orignally twin turbo...and it is DOHC

EJ20R - stock internals (forged maybe? who knows lol)
EJ20R heads - 252 cams
Rotated TD04
custom catless up/downpipe
3 inch turbo back exhaust - 1 high flow cat
headers
ford edis ignition w/ msd
660 sidefeed injectors
walboro 255lph
megasquirt 1 stand alone ecu
greddy profec b boost control
fmic

I'm thinking injectors, fuel pump, turbo, and built short block. How much of a difference in cams will I get between 252 and 272